Generally, a cyclone separating apparatus operates to separate dust and dirt using centrifugal force by generating a rotational current inside of the cyclone chamber. The cyclone separating apparatuses are widely used in a variety of fields. U.S. Pat. Nos. 3,425,192 and 4,373,228 disclose embodiments adopting the structure of the aforementioned cyclone separating apparatus to the vacuum cleaner. The above-mentioned U.S. Patents disclose the cyclone dust-collecting apparatus for separating dust from dust-ladened air through a plurality of cyclones. In the construction, large dust particles are separated by the first cyclone, and cleaned air flows into the second cyclone or the auxiliary cyclone where it is filtered again to separate small dust particles or dirt. Purified air is discharged to the outside. U.S. Pat. No. 3,425,192 discloses that the auxiliary cyclone is arranged on the upper part of the first cyclone so that large dust particles are separated at the main cyclone (the first cyclone) and partially purified air flows into the auxiliary cyclone, where small dust particles are separated. U.S. Pat. No. 4,373,228 discloses a plurality of cyclone units in which the auxiliary cyclones are installed inside of the first cyclone. The conventional cyclone separating apparatuses, however, have the following problems.
First, the structure where the first cyclone is connected to the auxiliary cyclone is complicated, and the suction force generated from the main body of the vacuum cleaner is hard to deliver, thus causing the suction operation and cleaning efficiency to deteriorate. Secondly, since the arrangement of the first cyclone and the auxiliary cyclone is not compact, the cyclone separating apparatus indispensably requires to be large enough to adequately perform the dust-collecting operation. Accordingly, the vacuum cleaner with such a cyclone separating apparatus is bulky, difficult to maintain and causes an inconvenience to a user to operate. Thirdly, the conventional cyclone separating apparatuses are problematic in that since a connection path between the first cyclone and the auxiliary cyclone is complicated, a production process is complicated and, therefore, the number of parts and production costs are increased.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.